The laser of choice for interferometry, ellipsometry and semicon inspection! TOPTICA has successfully developed a demonstration system of a high-power laser at the classical HeNe wavelength of 633 nm. The system employs mature near-infrared distributed-feedback (DFB) diode technology.

Using proprietary technology, the fundamental wavelength of 1266 nm is first amplified and then frequency-doubled to 633 nm. A reliable locking algorithm stabilizes the laser wavelength either to a low-power HeNe reference, or to an iodine transition. The laser exhibits an exceptionally stable performance, both in terms of output power and frequency: The relative frequency uncertainty is on the 10-8 level, even on time scales of 1000 hours. With an output greater than 100 mW, a single high-power laser replaces “bundles” of HeNe tubes in advanced test & measurement tasks.